Pinterest/瀑布流布局
一 加载页面时,先页面中对已有元素进行定位。
使用对象保存每一列的列高度和列索引如:var column = {index:0, height:0}；
使用列数组存放来这些对象。如：var columns = [column1,column2....]；
使用cloumns.sort(function(x,y){return x.height - y.height}); 可以找出最短/最长高度的列的索引。
元素left= 列索引* 列宽 ； 元素top = 最短一列的高度；
二 鼠标滚动到最短一列的底部时动态加载数据。
if（文档scrollTop + 视口高度 > 容器距离文档顶部位置 + 最短一列的高度）{
加载新内容
}
使用htmlElement.chidren属性可以只返回“htmlElement”的 元素类型子节点，不过IE中还会返回注释节点。htmlElement.childNodes 属性在非IE中除了返回元素类型子节点外，还返回注释和文本类型的子节点。要在childNodes里获取html元素节点，一般通过遍历然后比较 nodeType 进行过滤。每次 waterfall.appendChild(htmlElement.chidren[i]); htmlElement.chidren 里的元素个数减一，后面的元素自动向前移。
代码：
<!doctype html>
<html>
<head>
<meta charset="gb2312">
<title>Pinterest/瀑布流布局</title>
<style>
.waterfall{position:relative; margin:0 auto;}
.waterfall .item{210px; display:none}
.waterfall .item:hover{opacity: 0.9}
.loading{text-align:center; padding:20px 0 120px; }
</style>
</head>
<body>
<a href="javascript:void(null)" onClick="blank()">open</a>
<h1>Pinterest/瀑布流布局</h1>
<ul>
<li>加载页面，动态数据块，透明度为0, 对已有元素进行定位</li>
<li>问个瀑布流中的滚动加载数据问题？ 页面高度(scrollHeight)- 浏览器视口高度(offsetHeight) + 浏览器滚动高度(scrollTop)</li>
<li>鼠标滚动到最短一列的底部时加载数据</li>
</ul>
<h2>document clientWidth:</h2>
<script>
document.write(document.body.clientWidth + "<br>" + document.documentElement.clientWidth);
var data = ' <div class="item"> \
<img src="http://pic4.xihuan.me/dr/192_287_90/t02e9a2932e981c0892.jpg" width="191" height="287"> \
</div>\
\
<div class="item"> \
<img src="http://pic2.xihuan.me/dr/192_288_90/t023a00b8fd90f13bf6.jpg" width="191" height="288">\
</div>\
\
<div class="item">\
<img src="http://pic2.xihuan.me/dr/192_128_90/t0261c1649fa0049796.jpg" width="192" height="128">\
</div>\
\
<div class="item"> \
<img src="http://pic2.xihuan.me/dr/192_136_90/t02f6128c27a03ba1b4.jpg" width="192" height="136"> \
</div>\
\
<div class="item"> \
<img src="http://pic3.xihuan.me/dr/192_288_90/t02999b00e78b0305fe.jpg" width="192" height="288">\
</div>\
\
<div class="item">\
<img src="http://pic1.xihuan.me/dr/192_267_90/t0285ead0935b33176e.jpg" width="191" height="267">\
</div>\
\
<div class="item"> \
<img src="http://pic3.xihuan.me/dr/192_144_90/t02fa12b10de9a6d67a.jpg" width="192" height="144">\
</div>\
\
<div class="item" > \
<img src="http://pic4.xihuan.me/dr/192_192_90/t025e949d4862320f73.jpg" width="192" height="192"> \
</div>\
\
<div class="item">\
<img src="http://pic0.xihuan.me/dr/192_266_90/t02b313f975b4fe3068.jpg" width="192" height="266">\
</div>\
\
<div class="item" > \
<img src="http://pic0.xihuan.me/dr/192_302_90/t0214baf4ab88314b2b.jpg" width="192" height="302">\
</div>\
\
<div class="item">\
<img src="http://pic2.xihuan.me/dr/192_256_90/t020b4d6b44ee7f086d.jpg" width="192" height="256">\
</div>\
\
<div class="item"> \
<img src="http://pic4.xihuan.me/dr/192_288_90/t024968e7e08f88a459.jpg" width="192" height="288"> \
</div>\
\
<div class="item">\
<img width="191" height="251" src="http://pic0.xihuan.me/dr/192_251_90/t02af8a0a7824408fcc.jpg">\
</div>\
\
<div class="item">\
<img width="192" height="192" src="http://pic0.xihuan.me/dr/192_192_90/t02664c86dbada6a50e.jpg"> \
</div>\
\
<div class="item"> \
<img width="192" height="152" src="http://pic0.xihuan.me/dr/192_152_90/t02c218bfbdd123c42b.jpg"> \
</div>\
\
<div class="item"> \
<img width="191" height="241" src="http://pic3.xihuan.me/dr/192_241_90/t026c1546d982d42d38.jpg">\
</div>\
\
<div class="item">\
<img width="191" height="288" src="http://pic3.xihuan.me/dr/192_288_90/t0238004c02f31c6c0c.jpg">\
</div>\
\
<div class="item" > \
<img width="191" height="427" src="http://pic2.xihuan.me/dr/192_427_90/t023f32089c91e6d53d.jpg"> \
</div>\
\
<div class="item" >\
<img height="176" width="192" src="http://pic4.xihuan.me/dr/192_176_90/t02b7c4366b32e0335d.jpg">\
</div>';
</script>
<h2> document.documentElement.clientWidth</h2>
<p> document.body.clientWidth body 元素宽度<br>
document.documentElement.clientWidth html元素宽度
</p>
<h2>htmlElement.chidren</h2>
<p>
使用htmlElement.chidren属性可以只返回“htmlElement”的元素类型子节点，不过IE中还会返回注释节点。htmlElement.childNodes 属性在非IE中除了返回元素类型子节点外，还返回注释和文本类型的子节点。要在childNodes里获取html元素节点，一般通过遍历然后比较nodeType 进行过滤。
<br>
每次 waterfall.appendChild(htmlElement.chidren[i]); htmlElement.chidren 里的元素个数减一，后面的元素自动向前移。
</p>
<div class="wrap">
<div id="Waterfall" class="waterfall">
<div class="item">
<img src="http://pic4.xihuan.me/dr/192_287_90/t02e9a2932e981c0892.jpg" width="191" height="287">
</div>
<div class="item">
<img src="http://pic2.xihuan.me/dr/192_288_90/t023a00b8fd90f13bf6.jpg" width="191" height="288">
</div>
<div class="item">
<img src="http://pic2.xihuan.me/dr/192_128_90/t0261c1649fa0049796.jpg" width="192" height="128">
</div>
<div class="item">
<img src="http://pic2.xihuan.me/dr/192_136_90/t02f6128c27a03ba1b4.jpg" width="192" height="136">
</div>
<div class="item">
<img src="http://pic3.xihuan.me/dr/192_288_90/t02999b00e78b0305fe.jpg" width="192" height="288">
</div>
<div class="item">
<img src="http://pic1.xihuan.me/dr/192_267_90/t0285ead0935b33176e.jpg" width="191" height="267">
</div>
<div class="item">
<img src="http://pic3.xihuan.me/dr/192_144_90/t02fa12b10de9a6d67a.jpg" width="192" height="144">
</div>
<div class="item" >
<img src="http://pic4.xihuan.me/dr/192_192_90/t025e949d4862320f73.jpg" width="192" height="192">
</div>
<div class="item">
<img src="http://pic0.xihuan.me/dr/192_266_90/t02b313f975b4fe3068.jpg" width="192" height="266">
</div>
<div class="item" >
<img src="http://pic0.xihuan.me/dr/192_302_90/t0214baf4ab88314b2b.jpg" width="192" height="302">
</div>
<div class="item">
<img src="http://pic2.xihuan.me/dr/192_256_90/t020b4d6b44ee7f086d.jpg" width="192" height="256">
</div>
<div class="item">
<img src="http://pic4.xihuan.me/dr/192_288_90/t024968e7e08f88a459.jpg" width="192" height="288">
</div>
<div class="item">
<img width="191" height="251" src="http://pic0.xihuan.me/dr/192_251_90/t02af8a0a7824408fcc.jpg">
</div>
<div class="item">
<img width="192" height="192" src="http://pic0.xihuan.me/dr/192_192_90/t02664c86dbada6a50e.jpg">
</div>
<div class="item">
<img width="192" height="152" src="http://pic0.xihuan.me/dr/192_152_90/t02c218bfbdd123c42b.jpg">
</div>
<div class="item">
<img width="191" height="241" src="http://pic3.xihuan.me/dr/192_241_90/t026c1546d982d42d38.jpg">
</div>
<div class="item">
<img width="191" height="288" src="http://pic3.xihuan.me/dr/192_288_90/t0238004c02f31c6c0c.jpg">
</div>
<div class="item" >
<img width="191" height="427" src="http://pic2.xihuan.me/dr/192_427_90/t023f32089c91e6d53d.jpg">
</div>
<div class="item" >
<img height="176" width="192" src="http://pic4.xihuan.me/dr/192_176_90/t02b7c4366b32e0335d.jpg">
</div>
</div>
<div class="loading" id="loading">正在加载……</div>
</div>
<script>
var tool = {
//此方法为了避免在 ms 段时间内，多次执行func。常用 resize、scoll、mousemove等连续性事件中
buffer: function(func, ms, context){
var buffer;
return function(){
if(buffer) return;
buffer = setTimeout(function(){
func.call(this)
buffer = undefined;
},ms);
};
},
/*读取或设置元素的透明度*/
opacity: function(elem, val){
var setting = arguments.length > 1;
if("opacity" in elem.style){//elem.style["opacity"] 读取不到CSS class中的值
return setting ? elem.style["opacity"] = val : elem.style["opacity"];
}else{
if(elem.filters && elem.filters.alpha) {
return setting ? elem.filters.alpha["opacity"] = val*100 : elem.filters.alpha["opacity"]/100;
}
}
},
//获取或设置文档对象的scrollTop
//function([val])
documentScrollTop: function(val){
var elem = document;
return (val!== undefined) ?
elem.documentElement.scrollTop = elem.body.scrollTop = val :
Math.max(elem.documentElement.scrollTop, elem.body.scrollTop);
},
//function (elem) 获取elem在页面中的坐标
//return {top:xxx,left:xxx}
offset: function (elem){
var top , left;
if(!(elem && elem.offsetTop)) return null;
top = elem.offsetTop;
left = elem.offsetLeft;
while(elem = elem.offsetParent){
top += elem.offsetTop;
left += elem.offsetLeft;
}
return {top:top, left:left};
},
get: function(id){
return document.getElementById(id);
},
addEventListener: function(elem, type, handel){
if(elem.addEventListener){
elem.addEventListener(type, handel, false);
}else {
elem.attachEvent("on"+type, function(){
handel.call(elem, window.event);
});
}
}
};
function wrap(elem){
return new DomWrap(elem);
}
function DomWrap(elem){
this.core = tool;
this.dom = elem;
}
DomWrap.prototype={
on: function(type, handel){
this.core.addEventListener(this.dom, type, handel);
}
};
//Waterfall
(function(ns, dom){//dom:DomWrap
//静态私有成员
var viewportHeight = document.documentElement.clientHeight;
var minHeight = 0;
var columnCount = 5;
var columnWidth= 210;
var cloumns = [];
var waterfall = "";
var staticElems = [];
var baseTop = 0;
//初始化
function init(container){
waterfall = tool.get(container);
staticElems = waterfall.children;
baseTop = tool.offset(waterfall).top;
for(var i=0; i< columnCount; i ++){
cloumns[i] = {index:i, height:0};
}
waterfall.style.width = (columnWidth*columnCount)+"px";
dom(window).on("scroll",tool.buffer(onscroll,500));
position(staticElems);
}
//设置元素位置
function position(elems, append){
var left, top, cssText;
var appedElem = null;
var sortedCloumns = [];
for(var i=0, n= elems.length; i< n;) {
if(!(elems[i] && elems[i].nodeType ===1)) continue;
cloumns.sort(function(x,y){return x.height - y.height});
index = cloumns[0].index;
left = index * columnWidth
top = cloumns[0].height;
cssText = "display:block; position:absolute; left:" + left + "px; top:" + top + "px";
elems[i].style.cssText = cssText;
if(append){
apendItem = elems[i];
waterfall.appendChild(apendItem);
cloumns[0].height += apendItem.offsetHeight;
n--;
} else {
cloumns[0].height += elems[i].offsetHeight;
i++;
}
}
cloumns.sort(function(x,y){return x.height - y.height});
minHeight = cloumns[0].height;
waterfall.style.height = cloumns[cloumns.length-1].height + "px";
}
function appendItem(){
var fragment = document.createElement("div");
fragment.innerHTML = data;
position(fragment.children,true);
}
function onscroll(){
var scrollTop = tool.documentScrollTop();
if(scrollTop + viewportHeight > baseTop + minHeight ) {
//console.log("loading");
appendItem();
}
}
ns.watferfall = init;
}( window, wrap));
watferfall("Waterfall");
</script>
</body>
</html>